Bore pack exciter systems are used to rectify alternating current (Ac) and provide direct current (Dc) field excitation power for an electric power generator. The bore pack exciter is commonly mounted on the end of the generator. However, the high power bore pack exciter requires internal cooling to prevent overheating; and down time, not only of the exciter but also the power generator to which it supplies Dc field power. Power generating systems normally include a cooling system having a cooler to provide cooling air into the interior of the housing or frame of the power generator to be blown over the components within the power generator housing by fan blades attached to the rotating shaft of the generator. The fan forces the cooled air to flow along and around the heated parts of the generator, such as the coils, rings and laminations. Arrangements presently in use cause part of the cooling air which has flowed through the electric power generator to be directed to pass through the bore pack exciter, after which it is returned to the cooler for re- cooling and return to the power generator. However, the temperature of this cooling air has been elevated and its velocity reduced in passing through the generator, such that it does not provide efficient or effective cooling of the bore pack exciter. Also, for certain demanding applications, where size and weight of the power generation system may be limited, it becomes necessary to obtain increased bore pack exciter cooling over that provided by existing systems. The use of an additional cooler and/or fan to accomplish such increased cooling would add size and weight and would increase the cost of the power generation system.